donsutherland1

During the summer and early fall (early spring in the Southern Hemisphere), numerous daily and monthly high temperature records, including some all-time high temperature records, along with monthly mean temperature records were broken. A number of locations experienced their hottest summer on record. July 2020 was Phoenix’s hottest month on record. August 2020 was even hotter. Summer 2020 was, by far, Phoenix’s hottest summer on record. Parts of South America and Southern Africa are currently experiencing their most intense early spring heat on record. Research demonstrates that climate change has led to an increase in summertime high temperature records, which are tied to prolonged heat waves, by more than a factor of ten. There is approximately an 80% probability that the new records have been made possible by anthropogenic climate change. Further increases in such records are likely in coming decades as the world’s climate continues to warm. https://www.researchgate.net/publication/234114398_Global_increase_in_record-breaking_monthly-mean_temperatures

I’m not sure if the below paper has been posted here, but it allows for comparisons of Arctic sea ice volume during the first half of the 20th century, including the 1920-40 Arctic warming, and the rapid declines in volume today. The paper is: Arctic Sea Ice Volume Variability over 1901–2010: A Model-Based Reconstruction https://journals.ametsoc.org/jcli/article/32/15/4731/343909/Arctic-Sea-Ice-Volume-Variability-over-1901-2010-A

Phoenix recorded its hottest summer (June 1-August 31) on record. Anthropogentic climate change has been driving an observed global warming. Within that global climate context, Phoenix has experienced both a warming of its summers and a lengthening of its summer-like temperatures. If one looks back at the climate model projections for the RCP 4.5 scenario, one finds that the climate model projections run in 2005 were very accurate in depicting what the summer 2011-2020 period would be like. Looking ahead, the summer 2021-2030 period will likely be even warmer under the RCP 4.5 scenario. Phoenix: Summer 2011-20 High Temperatures and Projected 2021-30 High Temperatures:

A newly published paper revealed new evidence of a slowing of the Atlantic Meridional Overturning Circulation (AMOC) in response anthropogenic warming. The paper can found here.

Actually, I was referring to the counterproductive course initiated by the United States beginning in January 2017 with the withdrawal from the Paris Agreement and rollback of regulations that has been occurring since then.

On the recent policy path that was launched in 2017, that’s a plausible outcome. I suspect some of the adverse changes that were made will be reversed by new leadership in coming years.

The status quo tends to be “sticky” for lack of a better term. When companies, countries, or societies have done well under the status quo, complacency sets in and that hardens their determination to preserve the status quo, even when developments render it unsustainable and its extension leads to worse outcomes. It’s too soon to be sure about the U.S. as a whole, but status quo thinking currently constrains U.S. policy. Efforts to move away from the status quo are subjected to defeatist “can’t be done” thinking. Had today’s thinking that thwarts effective climate change policies and a rapid shift away from fossil fuels defined the nation’s effort during World War II, the Allied countries would likely have lost the war. Had it defined things at the time the Apollo Project was launched, humans would still be looking to the future when they could set foot on the moon. Had it constrained the Ozone Hole and Acid Rain responses, both problems would have continued to grow worse.

In the United States, there is little talk about binding medium-term commitments to 100% renewable energy. Any such commitments, where they exist, lie decades into the future to 2050 or later. In contrast, tiny New Zealand, which has so far demonstrated world-class leadership in managing the coronavirus pandemic, provides an example of leadership on the climate change policy front. Prime Minister Jacinda Ardern appears poised to commit to 100% renewable energy by 2030 if she is re-elected. Australia's SBS News reported: Looking to deepen her clean, green credentials in the lead-up to October's election, Jacinda Ardern has promised to bring forward New Zealand's renewable energy goal. If re-elected as prime minister, Ms Ardern says she'll end all non-renewable energy generation in New Zealand by the end of the decade. "The COVID-19 economic recovery represents a once in a generation opportunity to reshape New Zealand's energy system to be more renewable, faster, affordable and secure," she said on Thursday. https://www.sbs.com.au/news/jacinda-ardern-pledges-to-end-non-renewable-energy-generation-by-2030-if-she-s-re-elected As noted previously, the United States would do well to view the climate change crisis with the same urgency and undertake the same effort that was displayed in pursuing the Manhattan Project, Apollo Project, addressing the Ozone hole, and combating acid rain. All four examples demonstrate that ambitious and effective problem-solving can be achieved within tight time frames with sound leadership, even when new technologies must be invented. The biggest obstacles confronting the U.S. today are defeatist "can't be done" pessimism, outright denial of the climate change problem among a small but still not insignificant share of the public, and entrenched anti-science ideology among a segment of the population and political leaders.

A useful op-ed from 2018 on climate change from Gavin Schmidt, Director of NASA’s Goddard Institute of Space Studies: https://www.nytimes.com/2018/10/24/opinion/climate-change-global-warming-trump.html Excerpt: Like forensic detectives, climate scientists have developed a new array of tools in recent decades designed to skillfully calculate what the fingerprints of these changes look like, and more important, how they differ from one another. It turns out that increases in solar activity produce warming throughout the atmosphere, while carbon dioxide increases cooling in the upper atmosphere and warms the surface. Variations in ocean circulation distribute heat, while changes in the sun or in greenhouse gases change the total heat amount in the system. Air pollution, volcanoes and irrigation all cool the climate, while rising greenhouse gases warm it. Ozone depletion has increased the speed of the winds around Antarctica, affecting ocean circulation and sea ice. But even taking into account uncertainties in the amount of air pollution in the 19th century or in estimating global temperatures through time, scientists have concluded that the current warmth is impossible to explain without human contributions. It is on a par with the likelihood that a DNA match at a crime scene is purely coincidental.

While Phoenix was recording its hottest month on record in August, after having set the mark in July, the United Kingdom experienced a severe heat wave in August. Here’s a link to a post written by two UK Met Office authors: https://www.carbonbrief.org/met-office-the-uks-august-2020-heatwave Excerpt: During August 2020, temperatures exceeding 34C were recorded somewhere in the UK for six consecutive days. 34C has been recorded in the UK during seven out of the last 10 years, compared to seven out of the previous 50 years from 1961 to 2010. This suggests that temperatures of 34C or higher occurring at some point during the summer are becoming a more common occurrence.

It still varies quite a bit.

On JAXA, Arctic sea ice extent rose to 3.735 million square kilometers. The 2020 minimum figure was 3.555 million square kilometers. That figure will very likely be the final minimum extent for 2020.

I agree. The NHC is very clear what a tropical cyclone is: " A warm-core non-frontal synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and a closed surface wind circulation about a well-defined center." This is a very active season on account of developing La Nina conditions, wet conditions in Africa, and abnormally warm Atlantic waters. Prior to the season, NOAA, Colorado State, and Penn State forecasters all called near-record to possible record tropical activity.

On September 14, Arctic sea ice extent increased to 3.582 million square kilometers on JAXA.

Abstract: Pine Island Glacier and Thwaites Glacier in the Amundsen Sea Embayment are among the fastest changing outlet glaciers in West Antarctica with large consequences for global sea level. Yet, assessing how much and how fast both glaciers will weaken if these changes continue remains a major uncertainty as many of the processes that control their ice shelf weakening and grounding line retreat are not well understood. Here, we combine multisource satellite imagery with modeling to uncover the rapid development of damage areas in the shear zones of Pine Island and Thwaites ice shelves. These damage areas consist of highly crevassed areas and open fractures and are first signs that the shear zones of both ice shelves have structurally weakened over the past decade. Idealized model results reveal moreover that the damage initiates a feedback process where initial ice shelf weakening triggers the development of damage in their shear zones, which results in further speedup, shearing, and weakening, hence promoting additional damage development. This damage feedback potentially preconditions these ice shelves for disintegration and enhances grounding line retreat. The results of this study suggest that damage feedback processes are key to future ice shelf stability, grounding line retreat, and sea level contributions from Antarctica. Moreover, they underline the need for incorporating these feedback processes, which are currently not accounted for in most ice sheet models, to improve sea level rise projections. https://www.pnas.org/content/early/2020/09/08/1912890117

Here's a link to the paper: https://www.nature.com/articles/s41550-020-1174-4

1010 WINS Radio reported: An enormous chunk of Greenland’s ice cap has broken off in the far northeastern Arctic, a development that scientists say is evidence of rapid climate change. The glacier section that broke off is 110 square kilometers (42.3 square miles). It came off of the fjord called Nioghalvfjerdsfjorden, which is roughly 80 kilometers (50 miles) long and 20 kilometers (12 miles) wide, the National Geological Survey of Denmark and Greenland said Monday. The glacier is at the end of the Northeast Greenland Ice Stream, where it flows off the land and into the ocean. The BBC has an article on this development. That article can be found at: https://www.bbc.com/news/science-environment-54127279

It's too soon to tell.

I did read the replies. It's a disconcerting situation. Facebook, in its present state, undermines societal information literacy. It helps deprive the public of useful and important information. That's deeply unfortunate given its large membership.

That's a great analogy. Today, the scientific evidence is clear , overwhelming and unequivocal. Yet, if one peruses Social Media and political rhetoric, beliefs that run counter to the evidence persist. Those beliefs, even as they are sometimes cloaked in terms of uncertainty, are non-scientific. The uncertainty is exaggerated beyond what actually exists. Peer-reviewed data and empirical evidence are dismissed outright to preserve those beliefs. None of those beliefs have anything to do with science or the scientific process. Those beliefs are articles of faith, alone. That faith is incompatible with science and the scientific evidence. It is also a substantial barrier to the kind of reforms needed for society to begin to tackle the reality of climate change and its increasingly adverse consequences (severe heat, extreme wildfires, etc.). Those affected by the growing consequences of climate change have only tears. The status quo and its prophets bear some degree of responsibility for thwarting reforms that could begin to mitigate the risks that confront them.

The observations match what has been documented in the literature. There is also a fairly large body of peer-reviewed literature on the impact of climate change on wildfires. Climate change, not failures to "rake," forest management practices, etc., is the principal reason for the increase in severe wildfire seasons, not just in the U.S. but also parts of Europe, Asia, and Australia.

Arctic sea ice extent fell to 3.555 million square kilometers on JAXA.

For another perspective concerning the rising temperatures at Phoenix, if one takes a look at record high and record high-tying maximum temperatures, 167 of those daily records have occurred 2000 or later. Among those, 113 have occurred 2010 or later. These figures are based on 366 days. For the 92–day June-August period, 55 of those records have occurred 2000 or later; 48 have occurred 2010 or later. Phoenix’s daily climate record goes back to August 1895. Under RCP 4.5, Phoenix is projected to have an average high temperature of 107.1 by the mid-2020s. By the mid 2050s, the record-breaking summer of 2020 is projected to be the “new normal” so to speak.

From Rick Thomas: https://twitter.com/AlaskaWx/status/1304864366106349569?s=20

Arctic sea ice extent rose by just under 1,600 square kilometers to 3.564 million square kilometers on JAXA. It will probably be at least a week before it is certain that the 2020 minimum extent has been reached.